Base-Controlled Synthesis of Heteroatom-Embedded 9-Membered Cycloalkynes and 6-Membered Sultams through
Haoyang Liu1, Hailiang Xing1, Peilan Yu1
1School of Pharmacy and Food Engineering, Wuyi University, Jiangmen, Guangdong 529020, China.
Abstract:
A facile copper-catalyzed, base-controlled cyclization reaction has been developed for the synthesis of 9-membered cycloalkyne and 6-membered heterocycle sultams under mild conditions. This protocol utilizes a copper-catalyzed intramolecular A3 (alkyne-aldehyde-amine) coupling reaction to efficiently synthesize 9-membered cycloalkyne sultams in yields up to 90%. Alternatively, by substituting NaHCO3 with DBU, the protocol achieves selective deprotection of the N-propargyl group, thereby facilitating the formation of 6-membered heterocyclic sultams, also in high yields.
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